Evolution of surface gravity waves over a submarine canyon

The effects of a submarine canyon on the propagation of ocean surface waves are examined with a three-dimensional coupled-mode model for wave propagation over steep topography. Whereas the classical geometrical optics approximation predicts an abrupt transition from complete transmission at small incidence angles to no transmission at large angles, the full model predicts a more gradual transition with partial reflection/transmission that is sensitive to the canyon geometry and controlled by evanescent modes for small incidence angles and relatively short waves. Model results for large incidence angles are compared with data from directional wave buoys deployed around the rim and over Scripps Canyon, near San Diego, California, during the Nearshore Canyon Experiment (NCEX). Wave heights are observed to decay across the canyon by about a factor 5 over a distance shorter than a wavelength. Yet, a spectral refraction model predicts an even larger reduction by about a factor 10, because low frequency components cannot cross the canyon in the geometrical optics approximation. The coupled-mode model yields accurate results over and behind the canyon. These results show that although most of the wave energy is refractively trapped on the offshore rim of the canyon, a small fraction of the wave energy 'tunnels' across the canyon. Simplifications of the model that reduce it to the standard and modified mild slope equations also yield good results, indicating that evanescent modes and high order bottom slope effects are of minor importance for the energy transformation of waves propagating across depth contours at large oblique angles

Oceanic biogeochemical characteristic maps identified with holistic use of satellite, model and data

This is the final published version.Ocean province level plankton community exhibit heterogeneity across Arctic, Nordic, Atlantic Gyre and Southern Ocean provinces. GreenSeas research is an international FP7 consortium that includes Arctic, Atlantic and Southern Ocean based research teams who are analysing the planktonic ecosystem. We are looking at how the planktonic ecosystem responds to environmental and climate change. Using Earth Observation monitoring data we report new results on identifying generic plankton characteristics observable at a province level, and also touch on spatial and temporal trends that are evident using a holistic analysis framework. Using advanced statistical methods this framework compares and combines Earth Observation information together with an in-situ Oceanic plankton Analytical Database and up to 40 year ocean general circulation biogeochemical model (OGCBM) time series of the equivalent plankton and sea-state measures of this system. Specifically, we outline the use of the GreenSeas Analytical Database, which is a harmonised set of Oceanic in-situ plankton and sea-state measures covering different cruises and time periods. The Analytical Database information ranges from plankton community, primary production, nutrient cycling to physical sea state temperature and salinity measures. The combined analysis utilises current, 10 year+ Earth Observations of ocean colour and sea surface temperature metrics and interprets these together with biogeochemical model outputs from PELAGOS, ERSEM & NORWECOM model runs to help identify planktonic based biomes. Generic planktonic characteristic maps that are equivalently observable in both the Earth Observations and numerical models are reported on. Both ocean surface and sub-surface signals are analysed together with relevant Analytical Database biome extracts. We present the current results of this inter-comparison & discuss challenges of identifying the province level plankton dominance with the satellite, model and data. In particular we discuss the strategic importance of systematically analysing the knowledge present in the existing key long term Oceanic observation platforms through such holistic analysis frameworks. These maps help to enhance and improve current biogeochemical models, our understanding of the plankton community structure and predictions used for future assessment of climate change

The use of antibiotic-loaded bone cement and systemic antibiotic prophylactic use in 2,971,357 primary total knee arthroplasties from 2010 to 2020: an international register-based observational study among countries in Africa, Europe, North America, and Oceania

Background and purpose - Antibiotic-loaded bone cement (ALBC) and systemic antibiotic prophylaxis (SAP) have been used to reduce periprosthetic joint infection (PJI) rates. We investigated the use of ALBC and SAP in primary total knee arthroplasty (TKA).Patients and methods - This observational study is based on 2,971,357 primary TKAs reported in 2010-2020 to national/regional joint arthroplasty registries in Australia, Den-mark, Finland, Germany, Italy, the Netherlands, New Zealand, Norway, Romania, South Africa, Sweden, Switzerland, the UK, and the USA. Aggregate-level data on trends and types of bone cement, antibiotic agents, and doses and duration of SAP used was extracted from participating registries.Results - ALBC was used in 77% of the TKAs with variation ranging from 100% in Norway to 31% in the USA. Palacos R+G was the most common (62%) ALBC type used. The primary antibiotic used in ALBC was gentamicin (94%). Use of ALBC in combination with SAP was common prac-tice (77%). Cefazolin was the most common (32%) SAP agent. The doses and duration of SAP used varied from one single preoperative dosage as standard practice in Bolzano, Italy (98%) to 1-day 4 doses in Norway (83% of the 40,709 TKAs reported to the Norwegian arthroplasty register). Conclusion - The proportion of ALBC usage in pri-mary TKA varies internationally, with gentamicin being the most common antibiotic. ALBC in combination with SAP was common practice, with cefazolin the most common SAP agent. The type of ALBC and type, dose, and duration of SAP varied among participating countries.Orthopaedics, Trauma Surgery and Rehabilitatio

Changes in Infection Prevention Practices and Occurrence of Skin Symptoms among Healthcare Workers, Cleaners and Day-care Workers in Norway during the COVID-19 Pandemic

The COVID-19 pandemic has resulted in increased attention on infection prevention measures. This study aims to assess whether changes in hand hygiene procedures, use of personal protective equipment and moisturizers during the first year of the COVID-19 pandemic were associated with changes in the occurrence of skin symptoms among healthcare workers, cleaners, and day-care workers. A total of 602 participants (40%) responded to an electronic questionnaire, including questions on previous and current occupational exposure and skin problems. Increased frequency of hand washing, use of hand disinfectants, use of disposable gloves and moisturizers were all associated with an increased symptom score on the hands, wrists, forearms. Participants who increased their use of masks or respirators had a higher risk of facial skin symptoms, compared with those with non-increased occupational exposure. In conclusion, a change of behaviour among healthcare workers, cleaners and day-care workers during the first year of the COVID-19 pandemic, with an increase in occupational exposures and use of moisturizers, was associated with higher occurrence of facial skin symptoms and symptoms on the hands, wrists and forearms

Reliance on social security benefits by Swedish patients with ill-health attributed to dental fillings: a register-based cohort study

<p>Abstract</p> <p>Background</p> <p>Some people attribute their ill health to dental filling materials, experiencing a variety of symptoms. Yet, it is not known if they continue to financially support themselves by work or become reliant on different types of social security benefits. The aim of this study was to analyse reliance on different forms of social security benefits by patients who attribute their poor health to dental filling materials.</p> <p>Methods</p> <p>A longitudinal cohort study with a 13-year follow up. The subjects included were 505 patients attributing their ill health to dental restorative materials, who applied for subsidised filling replacement. They were compared to a cohort of matched controls representing the general population (three controls per patient). Annual individual data on disability pension, sick leave, unemployment benefits, and socio-demographic factors was obtained from Statistics Sweden. Generalized estimating equations were used to test for differences between cohorts in number of days on different types of social security benefits.</p> <p>Results</p> <p>The cohort of dental filling patients had a significantly higher number of days on sick leave and disability pension than the general population. The test of an overall interaction effect between time and cohort showed a significant difference between the two cohorts regarding both sick leave and disability pension. In the replacement cohort, the highest number of sick-leave days was recorded in the year they applied for subsidised replacement of fillings. While sick leave decreased following the year of application, the number of days on disability pension increased and peaked at the end of follow-up.</p> <p>Conclusions</p> <p>Ill health related to dental materials is likely to be associated with dependence on social security benefits. Dental filling replacement does not seem to improve workforce participation.</p

Identification and quantification of monomers released from dental composites using HPLC

The aim of this study was to detect and quantify the main residual monomers released from composites, using high performance liquid chromatography (HPLC). Discs were made with dental composites (Herculite XRV, Tetric Ceram and Filtek Z250) and immersed in deionized water at 37ºC for 28 days, with water changes in 1, 7, 14 and 21 days. The mean concentration of residual monomers were subject to the Kruskal-Wallis test (p<0.05). Tetric Ceram exhibited significantly higher concentrations of leached monomers. Bis-GMA was the monomer released in lower concentrations for all the materials. There was no statistical difference between the amounts of TEGDMA and UDMA. Most of the monomers demonstrated maximal concentration at the 7-day period. The HPLC analysis identified Bis-GMA, TEGDMA and UDMA in detectable quantities for all the tested composites.<br>A liberação de monômeros residuais pode afetar o comportamento clínico e a biocompatibilidade dos materiais resinosos. O objetivo deste estudo foi detectar e quantificar os principais monômeros residuais liberados de resinas compostas, usando cromatografia líquida de alta performance (HPLC). Discos foram construídos de resinas compostas de uso odontológico (Herculite XRV, Tetric Ceram and Filtek Z250) e imersos em água deionizada a 37ºC durante 28 dias, com mudanças de água em 24 horas, 7, 14 e 21 dias. As concentrações médias dos monômeros residuais foram submetidas ao teste de Kruskal-Wallis (p<0,05). Tetric Ceram apresentou as maiores concentrações de monômeros lixiviados. Bis-GMA foi o monômero liberado em menores concentrações para todos os materiais. Não houve diferença estatística significante entre TEGDMA e UDMA. A maioria dos monômeros demonstrou máxima concentração no período de 7 dias. A análise por meio de HPLC identificou Bis-GMA, TEGDMA e UDMA em quantidades detectáveis para todas as resinas compostas testadas